Escape behavior - brainstem and spinal cord circuitry and function.

Recent work has demonstrated that the neural circuits mediating escape reactions in lower vertebrates and mammals have a common framework, with only two excitatory central synapses in the reflex arc. This relatively direct linkage from sense organs to muscles and the fact that segments of the network also transmit other motor commands help guarantee that escape always has priority over ongoing behaviors. Yet, modulation and plasticity contribute some variability to the expression of escape and, therefore, to the adequacy of its survival function.